1. Field of the Invention
The present invention generally relates to a headgear, and, more particularly, to a headgear having a universal fit for a patient interface device, such as a gas delivery mask, and to a system for supplying a flow of gas to a patient that incorporates such a headgear.
2. Description of the Related Art
There are numerous situations where it is necessary or desirable to deliver a flow of breathing gas non-invasively to the airway of a patient, i.e., without intubating the patient or surgically inserting a tracheal tube in their esophagus. For example, it is known to ventilate a patient using a technique known as non-invasive ventilation. It is also known to deliver continuous positive airway pressure (CPAP) or variable airway pressure, which varies with the patient's respiratory cycle, to treat a medical disorder, such as sleep apnea syndrome, in particular, obstructive sleep apnea (OSA), or congestive heart failure.
Non-invasive ventilation and pressure support therapies involve the placement of a patient interface device, which is typically a nasal mask that covers the nose, a nasal/oral mask that covers the nose and mouth, or full face mask that covers the patient face, on the face of a patient. The patient interface device interfaces the ventilator or pressure support device with the airway of the patient, so that a flow of breathing gas can be delivered from the pressure/flow generating device to the airway of the patient. It is known to maintain such masks on the face of a wearer by a headgear having upper and lower straps, each having opposite ends threaded through connecting elements provided on the opposite sides and top of a mask. Because such masks are typically worn for an extended period of time, it is important the headgear maintain the mask in a tight enough seal against a patient's face without discomfort.
One such headgear is disclosed in U.S. Pat. No. 5,517,986 which is assigned to Respironics, Inc. of Pittsburgh, Pa., the assignee of the present application. The headgear of U.S. Pat. No. 5,517,986 which is incorporated by reference herein, includes a cap-like headpiece adapted to fit the crown and back of a patient's head. Lower straps provide a two-point connection with a gas delivery mask. Depending straps depending from the headpiece are connected to and moveable relative to the lower straps. Additionally, a pair of upper straps can be used to provide a four-point connection with the gas delivery mask if needed.
Another such headgear 10 manufactured by Respironics, Inc. is illustrated in FIG. 1. Headgear 10 comprises five straps 12, 14, 16, 18, 20 extending in a star-like manner from a rear joining piece 22, which is positionable along the rear portion of a patient's head. The three uppermost straps 12, 14, 16 are adapted to fit on the patient's head. Center top strap 12 extends from joining piece 22 across the top of the patient's head to the patient's forehead. Upper side straps 14, 16 on either side of top strap 12 extend from joining piece 22 along the sides of a patient's head above the ears to attach to top strap 12 at the patient's forehead. Top strap 12 includes a pair of elongated openings 24 through which upper side straps 14, 16 are threaded.
All of the straps include two components of a hook and loop fastener such as VELCRO. The exterior of the straps include a loop fastener portion, and a hook fastener tab portion 26 is attached to the end of each strap. When securing or fastening, the end of each upper side strap 14, 16 is bent back on itself to adhere hook fastener tab portion 26 to the exterior of the straps including the loop fastener portion. More specifically, hook fastener tab portion 26 of top strap 12 is adapted to be threaded through a connecting element of the gas delivery mask and then bent back on itself to adhere the hook fastener tab portion to the exterior loop fastener portion.
Lower connecting straps 18, 20 are adapted to be brought forward from rear joining piece 22 beneath the patient's ear and threaded through connecting elements on either side of the gas delivery mask. Tab portions 26 are bent back to adhere to the exterior loop fastener portion of lower connecting straps 18, 20.
Conventional headgear 10 provides a convenient three-point headgear yet lacks adjustability in the cross direction of the head. Further, headgear 10 lacks the ability to prevent top strap 12 from shifting on the patient's head in use. Therefore, a need exists for a headgear which is easy to use and adjust.